NS7520B-1-C36 Digi International, NS7520B-1-C36 Datasheet - Page 129

• Manufacturer Part Number: NS7520B-1-C36
• Description: IC ARM MICROPROCESSOR 177BGA
• Manufacturer: Digi International
• Series: NET+ARM®r

Specifications of NS7520B-1-C36

• Applications: Network Processor
• Core Processor: ARM7
• Program Memory Type: External Program Memory
• Controller Series: -
• Ram Size: External
• Interface: EBI/EMI, Ethernet, DMA, SPI, UART
• Number Of I /o: 16
• Voltage - Supply: 1.4 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 177-LFBGA
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Command definitions
The NS7520 provides the A10/AP multiplexing function using the CAS0_ pin. During
the active command, the CAS0_ pin is driven with the logical value of one of the
address bits A[21:18] as a function of the port size configuration defined in Chip
Select Option Register A and the mux mode defined in the Chip Select Base Address
register.
This table defines which address bit is driven in each situation:
During the read or write commands, the NS7520 drives a 0 on the CAS0_ pin
(indicating that automatic precharge should not be performed). During the precharge
command, the NS7520 drives a 1 on the CAS0_ pin (indicating that all banks should be
precharged.)
SDRAMs operate according to a series of command codes that are issued while chip
select input is active low. The command codes are registered using the low-to-high
transition of the synchronous clock. NS7520 implementation requires that all SDRAMs
are synchronized to the NS7520 BCLK signal.
Table 45: SDRAM command definitions
0
1
Inhibit
NOP
Active
Read
Write
Burst Term
Precharge
Refresh
Mux mode
Command
1
0
0
0
0
0
0
0
CSx_
20
21
x32
X
X
Bank/row
Column
Column
X
X
X
A13:0
19
20
x16
X
1
0
1
1
1
0
0
CAS3_ RAS#
18
19
x8
w w w . d i g i e m b e d d e d . c o m
X
1
1
0
0
1
1
0
CAS2_ CAS#
M e m o r y C o n t r o l l e r M o d u l e
X
1
1
1
0
0
0
1
CAS1_ WE#
X
X
A10
0
0
X
1
X
CAS0_ A10/AP
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